156 



THE OAK. 



paucity of water at those parts, the parasite taking much 

 of that which reaches the injured place, and the impov- 

 erished wood allowing less to pass than it would normally 

 have done. 



Among the fungi there are several enemies to the 

 oak-tree. The leaves are attacked by Phyllactinia, one 



FIG. 41. Loranthus europceus. A. Lower part of stem attached to branch 

 of oak, both denuded of cortex. B. Longitudinal section through one 

 of the haustorial strands, showing its progress year by year, as the 

 branch thickens. C. Transverse section, through a branch which 

 has long been badly infested with the Lo ran thus ; a a, dead remains 

 of old haustorial strands; b J, young Loranthus plants developed as 

 buds from the older ones. The asterisks mark still younger speci- 

 mens. (Ilartig.) 



of the mildews, which forms white networks, like spiders' 

 webs, on their surfaces. Numerous small ascomycetous 

 fungi are found on the dying and dead leaves, but these 

 do not directly injure the living tree. 



Other fungi are found in the cortex, and one of the 

 most interesting of these is a red Nectria, the spores of 



